imagecolorat

(PHP 4, PHP 5, PHP 7)

imagecolorat — Get the index of the color of a pixel

Description

int imagecolorat ( resource $image , int $x , int $y )

Returns the index of the color of the pixel at the specified location in the image specified by image.

If the image is a truecolor image, this function returns the RGB value of that pixel as integer. Use bitshifting and masking to access the distinct red, green and blue component values:

Parameters

`image`

An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().

x

x-coordinate of the point.

y

y-coordinate of the point.

Return Values

Returns the index of the color.

Examples

Example #1 Access distinct RGB values

<?php
$im?=?imagecreatefrompng("php.png");
$rgb?=?imagecolorat($im,?10,?15);
$r?=?($rgb?>>?16)?&?0xFF;
$g?=?($rgb?>>?8)?&?0xFF;
$b?=?$rgb?&?0xFF;

var_dump($r,?$g,?$b);
?>

The above example will output something similar to:

int(119)
int(123)
int(180)

Example #2 Human-readable RGB values using imagecolorsforindex()

<?php
$im?=?imagecreatefrompng("php.png");
$rgb?=?imagecolorat($im,?10,?15);

$colors?=?imagecolorsforindex($im,?$rgb);

var_dump($colors);
?>

The above example will output something similar to:

array(4) {
  ["red"]=>
  int(119)
  ["green"]=>
  int(123)
  ["blue"]=>
  int(180)
  ["alpha"]=>
  int(127)
}

Description

Parameters

Return Values

Examples

See Also